The effect of botulinum toxin injections on the nasolabial fold.

The use of botulinum toxin A (Botox; Allergan, Irvine, Calif.) for cosmetic purposes was first described in the medical literature in 1992. The author has been using botulinum toxin A in his practice for cosmetic purposes since 1991. In May of 1992, he began using Botox for improvement of the nasolabial folds. An experience of over 1000 injections to the nasolabial folds in more than 200 unique patients is presented. Technique and selection criteria have changed greatly during the past 10 years, and this evolution is discussed. The keys to achieving adequate correction and satisfied patients when treating the nasolabial fold are proper diagnosis of what is causing the fold and careful patient selection.